The following is our recommended approach for sharing content from your live Production account to you Staging account (Only relevant for when utilizing two different accounts), in order to allow stressing your new features in a realistic environment.
Assuming you've cloned your Production database, and use it to reference images on your staging account. those images won't exist there obviously.
Using our upload-mapping feature you can create a mapping between a directory in your Staging account (e.g. the root directory '/') to another URL prefix (e.g. on the Production account 'http://res.cloudinary.com/<cloud-name-prod>/image/upload/').
This way, every non existing image on your Staging account will be seamlessly and silently migrated from Production to Staging and delivered at your request.
This way you'll be both preserving the folder structure and retaining flexibility with the synchronization between the two accounts. Furthermore, your production account will stay untouched during the whole process.
At any point you can delete images from the Staging account if needed, this won't affect the Production account.